Railroad and industrial vehicle disk brake

Description

[0001] The present invention relates to a railroad and industrial vehicle disk brake .

[0002] As is known, disk brakes undergo severe stress, and optimum braking action depends on effective transmission of the braking force from the pad to the disk.

[0003] Research over the past few years has shown more is to be gained from a number of friction bodies on one pad than from one large friction body.

[0004] European Patent EP 1099061 describes a disk brake pad, in particular for railroad vehicles, comprising a number of friction members fixed to a supporting plate. Each friction member is elongated in shape, is fixed to the supporting plate by two rivets, and is positioned differently from the others with respect to concentric circles of the disk, while still maintaining an angle α of 0°<α≤45° with respect to the concentric circles of the disk.

[0005] The Applicant has surprisingly discovered that curved elongated friction members, all located along concentric circles of the disk, provide for improving performance in terms of both braking efficiency and noise.

[0006] It is an object of the present invention to provide a railroad and industrial vehicle disk brake with the characteristics indicated in Claim 1, and the preferred characteristics indicated in Claims 2-9.

[0007] Two non-limiting embodiments of the present invention will be described by way of example with reference to the accompanying drawings, in which :

Figure 1 shows a partly transparent plan view of a first embodiment of the pad according to the present invention;

Figure 2 shows a partly transparent plan view of a second embodiment of the pad according to the present invention;

Figure 3 shows a plan view of a detail common to both the Figure 1 and 2 embodiments;

Figure 4 shows a plan view of another detail common to both the Figure 1 and 2 embodiments;

Figure 5 shows a graph of noise test results of a cast iron disk brake;

Figure 6 shows a graph of noise test results of a steel disk brake.

[0008] Number 1 in Figure 1 indicates as a whole a first embodiment of the pad according to the present invention.

[0009] Pad 1 substantially comprises a supporting plate 2; and eight friction members 3, each fixed to supporting plate 2 by one rivet 4.

[0010] Each friction member 3 is elongated in shape, and defined by two parallel curved long sides 5a and 5b.

[0011] Friction members 3 are fixed to supporting plate 2 so that the curves of sides 5a and 5b form an angle of 0° with respective concentric circles X of the disk D on which pad 1 acts.

[0012] In figure 1 the evidence of such a feature is shown only for one friction member 3 for sake of simplicity.

[0013] Each friction member 3 thus has an elongated friction surface defined by two curved long sides located in use along concentric circles X of disk D.

[0014] Given that railroad and industrial vehicle disk brake pads have only one position with respect to the disk, it is the Applicant's opinion that the position of the friction members in the pad is definable, for patent purposes, by defining their position with respect to the disk.

[0015] More specifically, friction members 3 are substantially rectangular, with two curved parallel long sides.

[0016] Each friction member 3 is fitted with a strengthener 6 (Figure 3) incorporated in friction member 3, leaving a fastening surface of the strengthener exposed, i.e. the fastening surface of strengthener 6 is positioned flush with the surface of friction member 3 facing the supporting plate.

[0017] As shown in Figure 3, each strengthener 6 comprises a plate 7, in which are formed a central hole 8 for rivet 4, and two circular teeth 9 extending perpendicularly on opposite sides of central hole 8 and which, as described below, aid in preventing rotation of friction member 3. Each strengthener 6 also comprises two fastening portions 10 located at the two ends of plate 7, and each having two fastening teeth 11 extending inside friction member 3, perpendicularly to plate 7 and on the opposite side to teeth 9.

[0018] Pad 1 comprises a number of antirotation members 12 (one shown in Figure 4), each of which has a first face fitted to supporting plate 2, and a second face fitted to a respective strengthener 6.

[0019] As shown in Figure 4, each antirotation member 12 comprises a plate 13, in which are formed a central hole 14 for rivet 4, and two holes 15 for housing teeth 9 of strengthener 6.

[0020] Each antirotation member 12 has two recesses 16, each formed along a respective side 17 of plate 13, and each housing a respective rotation-lock pin (not shown for the sake of simplicity) extending from supporting plate 2.

[0021] As will be clear from the above description, the arrangement of the friction members is an essential characteristic of the present invention and must therefore be maintained during operation of the brake. Hence the need for antirotation members, which are even more necessary in view of the fact that each friction member is only fixed to the supporting plate 2, by one rivet 4, about which it can therefore rotate.

[0022] The fact that strengthener 6 is integral with, i.e. incorporated in, friction member 3 and locked by teeth 9 cooperating with holes 15 in antirotation member 12, in turn locked to supporting plate 2 by recesses 16, ensures friction members 3 are held in position on the pad during operation.

[0023] Antirotation members 12 also serve as spacers to allow air to circulate between friction members 3 and supporting plate 2.

[0024] Despite this further advantage of antirotation members 12, the wider protective scope of the pad according to the present invention also covers different antirotation means, provided they are equally capable of maintaining the position of the friction members during operation.

[0025] Number 21 in Figure 2 indicates as a whole a second embodiment of the disk brake pad according to the present invention.

[0026] Identical parts of pads 21 and 1 are indicated using the same reference numbers, with no further description.

[0027] Pad 21 substantially differs from pad 1 as to the shape of the friction members. Pad 21 comprises eight substantially trapezoidal friction members 22, the major and minor base sides of which are curved to achieve the required angle with respect to the concentric circles X of disk D.

[0028] In this case, too, friction members 22 are elongated in shape and defined by two parallel curved long sides 23a, 23b, but, unlike friction members 3, have two long sides of different lengths, despite both defining the elongated shape.

[0029] In figure 2 the evidence of such a feature is shown only for one friction member 22 for sake of simplicity.

[0030] Friction members 22 have a possible further advantage over friction members 3, by having a longer side, and so providing greater friction, where circumferential speed is greater.

[0031] Figures 5 and 6 show the noise test results of a 640x110 mm cast iron disk and steel disk respectively.

[0032] Noise testing was conducted under the same conditions using pad 1 as described above, and a typical known control pad. More specifically, the control pad comprised triangular friction members positioned differently with respect to the concentric circles of the disk and made of the same material as the friction members of pad 1.

[0033] Noise was recorded over three sets of braking operations (from 1 to 9, from 10 to 18, and from 19 to 27) at different pressures. Each set comprised three braking operations at a disk speed of 50 km/h, three at a disk speed of 70 km/h, and three at a disk speed of 100 km/h. These speeds were chosen to simulate train speed nearing or entering a station, i.e. where noise level is most important.

[0034] As shown by the results in decibels in the Figure 5 and 6 graphs, the pads according to the present invention have a much lower noise level than the control pads, with no impairment in braking efficiency.

Claims

1. A railroad and industrial vehicle disk brake comprising a brake disk (D) and a disk brake pad (1; 21) which comprises a supporting plate (2) and a number of friction members (3; 22) fixed to said supporting plate (2) with the interposition of antirotation means (6, 12); said disk brake being characterized in that each friction member (3; 22) is elongated in shape, with two curved parallel long sides (5a, 5b); in that each friction member (3; 22) is fixed to said supporting plate (2) so that the curves of the long sides (5a, 5b) form a substantially 0° angle with respective concentric circles (X) of the disk (D) to which the pad (1) applies a braking force.

2. A railroad and industrial vehicle disk brake as claimed in Claim 1, characterized in that each of said friction members (3; 22) is fixed to said supporting plate (2) by one rivet (4).

3. A railroad and industrial vehicle disk brake as claimed in Claim 1 or 2, characterized in that said antirotation means comprise a strengthener (6) incorporated in said friction member (3; 22); and an antirotation member (12) which, on one side, is fixed to said supporting plate (2), and, on the other side, cooperates in antirotation manner with the strengthener (6).

4. A railroad and industrial vehicle disk brake as claimed in Claim 3, characterized in that each strengthener (6) comprises a plate (7), in which are formed a central hole (8) for the rivet (4), and two lock teeth (9).

5. A railroad and industrial vehicle disk brake as claimed in Claim 4, characterized in that each strengthener (6) comprises two fastening portions (10) located at the two ends of the plate (7), and each having two teeth (11) extending inside the friction member (3), perpendicularly to the plate (7) and on the opposite side to the lock teeth (9).

6. A railroad and industrial vehicle disk brake as claimed in Claim 5, characterized in that each antirotation member (12) comprises a plate (13), in which are formed a central hole (14) for the rivet (4), and two holes (15) for housing the lock teeth (9).

7. A railroad and industrial vehicle disk brake as claimed in Claim 6, characterized in that each antirotation member (12) comprises two recesses (16) formed along respective sides (17) of the plate (13) and for housing respective rotation-lock members extending from the supporting plate (2).

8. A railroad and industrial vehicle disk brake as claimed in any one of the foregoing Claims, characterized in that said friction members (3) are substantially rectangular.

9. A railroad and industrial vehicle disk brake as claimed in any one of Claims 1 to 7, characterized in that said friction members (22) are substantially trapezoidal.

Ansprüche

1. Scheibenbremse für Schienen- und Industriefahrzeuge mit einer Bremsscheibe (D) und einem Scheibenbremsbelag (1; 21), der eine Halteplatte (2) und mehrere Reibungselemente (3; 22) aufweist, die über eine zwischen den Reibungselementen und der Halteplatte angeordnete Verdrehsicherungseinrichtung (6, 12) an der Hal-teplatte (2) befestigt sind,
wobei die Scheibenbremse dadurch gekennzeichnet ist, dass
jedes Reibungselement (3; 22) eine längliche Form mit zwei gekrümmten, parallelen langen Seiten (5a, 5b) hat; und
jedes Reibungselement (3; 22) an der Halteplatte (2) derart befestigt ist, dass die Kurven der langen Seiten (5a, 5b) einen Winkel von im Wesentlichen 0° bezüglich konzentrischen Kreisen (X) der Bremsscheibe (D) bilden, auf die die Beläge (1) eine Bremskraft ausüben.

2. Scheibenbremse für Schienen- und Industriefahrzeuge nach Anspruch 1, dadurch gekennzeichnet, dass jedes der Reibungselemente (3; 22) durch eine Niete (4) an der Halteplatte (2) befestigt ist.

3. Scheibenbremse für Schienen- und Industriefahrzeuge nach Anspruch 1 oder 2,
dadurch gekennzeichnet, dass
die Verdrehsicherungseinrichtung ein im Reibungselement (3; 22) integriertes Verstärkungselement (6) und ein Verdrehsicherungselement (12) aufweist, das an einer Seite an der Halteplatte (2) befestigt ist und an der anderen Seite auf eine verdrehsichere Weise mit der Verstärkung (6) zusammenwirkt.

4. Scheibenbremse für Schienen- und Industriefahrzeuge nach Anspruch 3, dadurch gekennzeichnet, dass jede Verstärkung (6) eine Platte (7) aufweist, in der ein Mittelloch (8) für die Niete (4) und zwei Arretierzähne (9) ausgebildet sind.

5. Scheibenbremse für Schienen- und Industriefahrzeuge nach Anspruch 4, dadurch gekennzeichnet, dass jedes Verstärkungselement (6) zwei Befestigungsabschnitte (10) aufweist, die an den beiden Enden der Platte (7) angeordnet sind und jeweils zwei Zähne (11) aufweisen, die sich senkrecht zur Platte (7) und auf der den Arretierzähnen (9) gegenüberliegenden Seite in das Reibungselement (3) erstrecken.

6. Scheibenbremse für Schienen- und Industriefahrzeuge nach Anspruch 5, dadurch gekennzeichnet, dass jedes Verdrehsicherungselement (12) eine Platte (13) aufweist, in der ein Mittelloch (14) für die Niete (4) und zwei Löcher (15) zum Aufnehmen der Arretierzähne (9) ausgebildet sind.

7. Scheibenbremse für Schienen- und Industriefahrzeuge nach Anspruch 6, dadurch gekennzeichnet, dass jedes Verdrehsicherungselement (12) zwei entlang jeweiligen Seiten (17) der Platte (13) ausgebildete Vertiefungen (16) zum Aufnehmen jeweiliger Rotationssicherungselemente aufweist, die sich von der Halteplatte (2) erstrecken.

8. Scheibenbremse für Schienen- und Industriefahrzeuge nach einem der vorangehenden Ansprüche, dadurch gekennzeichnet, dass die Reibungselemente (3) im Wesentlichen rechteckig ausgebildet sind.

9. Scheibenbremse für Schienen- und Industriefahrzeuge nach einem der Ansprüche 1 bis 7, dadurch gekennzeichnet, dass die Reibungselemente (22) im Wesentlichen trapezförmig ausgebildet sind.

Revendications

1. Frein à disque pour véhicule ferroviaire et industriel comprenant un frein à disque (D) et une plaquette de frein à disque (1 ; 21) qui comprend une plaque de support (2) et un certain nombre d'éléments de friction (3 ; 22) fixés à ladite plaque de support (2) avec l'interposition de moyens anti-rotation (6, 12) ; ledit frein à disque étant caractérisé en ce que chaque élément de friction (3 ; 22) a une forme allongée, avec deux côtés longs parallèles incurvés (5a, 5b) ; en ce que chaque élément de friction (3 ; 22) est fixé à ladite plaque de support (2) de sorte que les courbes des côtés longs (5a, 5b) forment sensiblement un angle de 0° avec des cercles concentriques (X) respectifs du disque (D) sur lequel la plaquette (1) applique une force de freinage.

2. Frein à disque pour véhicule ferroviaire et industriel selon la revendication 1, caractérisé en ce que chacun desdits éléments de friction (3 ; 22) est fixé sur ladite plaque de support (2) par un rivet (4).

3. Frein à disque pour véhicule ferroviaire et industriel selon la revendication 1 ou 2, caractérisé en ce que lesdits moyens anti-rotation comprennent un renforçateur (6) incorporé dans ledit élément de friction (3 ; 22) ; et un élément anti-rotation (12) qui, d'un côté, est fixé sur ladite plaque de support (2), et de l'autre côté, coopère d'une manière antirotative avec le renforçateur (6).

4. Frein à disque pour véhicule ferroviaire et industriel selon la revendication 3, caractérisé en ce que chaque renforçateur (6) comprend une plaque (7), dans laquelle sont formés un trou central (8) pour le rivet (4) et deux dents de verrouillage (9).

5. Frein à disque pour véhicule ferroviaire et industriel selon la revendication 4, caractérisé en ce que chaque renforçateur (6) comprend deux parties de fixation (10) positionnées aux deux extrémités de la plaque (7), et chacune ayant deux dents (11) s'étendant à l'intérieur de l'élément de friction (3), perpendiculairement à la plaque (7) et du côté opposé aux dents de verrouillage (9).

6. Frein à disque pour véhicule ferroviaire et industriel selon la revendication 5, caractérisé en ce que chaque élément anti-rotation (12) comprend une plaque (13), dans laquelle sont formés un trou central (14) pour le rivet (4), et deux trous (15) pour loger les dents de verrouillage (9).

7. Frein à disque pour véhicule ferroviaire et industriel selon la revendication 6, caractérisé en ce que chaque élément anti-rotation (12) comprend deux évidements (16) formés le long de côtés (17) respectifs de la plaque (13) et pour loger des éléments de verrouillage de rotation respectifs s'étendant à partir de la plaque de support (2).

8. Frein à disque pour véhicule ferroviaire et industriel selon l'une quelconque des revendications précédentes, caractérisé en ce que lesdits éléments de friction (3) sont sensiblement rectangulaires.

9. Frein à disque pour véhicule ferroviaire et industriel selon l'une quelconque des revendications 1 à 7, caractérisé en ce que lesdits éléments de friction (22) sont sensiblement trapézoïdaux.

Drawing